Article
Chemistry, Organic
Yu-Xia Liu, Zhi-Wei Ma, Chuan-Chuan Wang, Qian Li, Wen-Peng Mai
Summary: This study demonstrates the application of isosteviol-derived bifunctional primary amine-squaramide organocatalysts in the Michael addition reaction between nitroalkenes and acetophenone, yielding high yields and good enantioselectivity at room temperature.
LETTERS IN ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Sijing Wang, Cefei Zhang, Da Li, Yuqiao Zhou, Zhishan Su, Xiaoming Feng, Shunxi Dong
Summary: N-heterocyclic olefins (NHOs) with electron-rich and highly polarized C=C double bond possess strong basicity and high nucleophilicity due to the donating property of nitrogen atoms. In this study, a new type of chiral aminederived C-2-symmetric NHOs was developed and used as efficient chiral bifunctional organocatalysts for asymmetric alpha-functionalization of beta-ketoesters. With as low as 0.1 mol% catalyst loading, the desired amination and trifluoromethylthiolation products were obtained in good yields with high enantioselectivities (up to 99% yield and 99% ee). Experimental studies and theoretical calculation revealed the crucial role of hydrogen-bonding interaction upon protonation and other weak interactions between substrate and catalyst in enantiocontrol.
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Chemistry, Organic
Howard Diaz-Salazar, Eddy I. Jimenez, Wilmer E. Vallejo Narvaez, Tomas Rocha-Rinza, Marcos Hernandez-Rodriguez
Summary: The study analyzed the reactivity of bifunctional squaramides with benzyl-like fragments in a Michael addition reaction, finding that non-cyclic benzyl substituents exhibited better selectivity than chiral phenylethyl analogs. The cyclic substituents showed varying results, with non-chiral tricyclic groups having lower selectivity due to unfavorable orientation of the phenyl group, while chiral 1-tetrahydronaphthyl groups seemed to offer optimal aryl ring disposition. A multivariate linear regression model was used to correlate these trends with the strength of pi contacts and energy required for active conformation adoption. The model suggested that the most selective catalyst incorporating 1-aminotetraline amine could be explained by the phenyl group being in its lowest energy conformation and having a double inductive effect from vicinal alkyl groups, leading to high selectivities across different nucleophiles and electrophiles. Additionally, quantum chemical topology analysis revealed that the transition state to the major enantiomer formed additional hydrogen bonds with the nucleophile and had a stronger association with the electrophile.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Daiki Ishii, Shin-ichi Hirashima, Kosuke Nakashima, Hiroshi Akutsu, Takaaki Sakai, Yasuyuki Matsushima, Masahiro Kawada, Tsuyoshi Miura
Summary: A new organocatalyst efficiently promotes the asymmetric direct vinylogous conjugate additions of alpha-angelica lactones to benzoyl acrylonitrile derivatives, resulting in products with excellent enantioselectivities. The chiral gamma,gamma-disubstituted gamma-butenolides obtained can be readily transformed to valuable synthetic intermediates.
Article
Chemistry, Multidisciplinary
Yujiro Hayashi, Shusuke Hattori, Seitaro Koshino
Summary: Flow reactions using an immobilized diphenylprolinol alkyl ether catalyst 2 were investigated for alpha,beta-unsaturated aldehydes and nitroalkanes. The reactions showed fast reaction rates and excellent enantioselectivity with good overall yields and turnover numbers.
CHEMISTRY-AN ASIAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Zubeda Begum, Haruka Sannabe, Chigusa Seki, Yuko Okuyama, Eunsang Kwon, Koji Uwai, Michio Tokiwa, Suguru Tokiwa, Mitsuhiro Takeshita, Hiroto Nakano
Summary: Simple primary beta-amino alcohols act as efficient organocatalysts in the asymmetric Michael addition of beta-keto esters with nitroalkenes, producing highly pure chiral Michael adducts. The choice of catalyst and reaction temperature determines the enantiomeric outcome of the adducts.
Article
Chemistry, Organic
Cornelius Gartner, Christoph Schneider
Summary: We report a cooperative palladium- and Bronsted acid-catalyzed strategy for the first enantioselective annulation of in situ generated alpha,beta-unsaturated N-acyliminium ions with chiral metal enolates. Novel polycyclic oxoisoindoles with three contiguous stereogenic centers were obtained with good yields, excellent enantiocontrol, and moderate to good diastereoselectivity. The utility of this process was demonstrated by their conversion to synthetically valuable scaffolds.
Article
Chemistry, Organic
Nariyoshi Umekubo, Tohru Taniguchi, Kenji Monde, Yujiro Hayashi
Summary: Bicyclo[2.2.2]octane derivatives with a quaternary bridgehead carbon were synthesized in nearly optically pure form with excellent diastereoselectivity using diphenylprolinol silyl ether mediated domino Michael/Michael reaction of alpha,beta-unsaturated aldehyde and cyclohex-2-en-1-one containing an electron-withdrawing group at the 3-position. Carbonitrile, alkoxycarbonyl, and sulfonyl substituents proved to be effective electron-withdrawing groups at the 3-position of cyclohex-2-en-1-one.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Haoyi Sun, Yongcheng Guo, Huajie Li, Meiling Wang, Tiandi Ding, Ying Zhi, Kun Zhao, Qingqiang Yao
Summary: A highly efficient method has been developed for the synthesis of (2-nitro-1-phenylethyl)malononitriles through a Michael addition reaction. The reaction takes place with excellent yields (90-98%) under mild conditions, providing a scalable approach to a series of the title compounds. An asymmetric version of the reaction has also been briefly explored.
Article
Chemistry, Organic
Jiang-Song Zhai, Da-Ming Du
Summary: A bifunctional thiourea-catalyzed asymmetric [3 + 2] annulation reaction has been developed to synthesize chiral dispiro[indene-pyrrolidine-pyrimidine] compounds from 2-isothiocyanato-1-indanones and barbiturate-based olefins. The reaction has shown excellent yields and stereoselectivities. The synthetic utility of the products has been demonstrated through gram-scale synthesis, one-pot three-component reactions, and further transformation experiments.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Organic
Yi-Ren Zhu, Jie Xu, Hui-Fang Jiang, Rui-Jing Fang, Yan-Jun Zhang, Lu Chen, Chen Sun, Fei Xiong
Summary: This article reviews the application of bifunctional sulfonamide as a hydrogen-bonding catalyst in asymmetric organocatalysis after 2011, highlighting asymmetric processes such as aldol reaction, Michael addition, Mannich reaction, desymmetrization, and cyclization.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Mahmoud A. Abdelkawy, Christopher Davin, El-Saied A. Aly, Mahmoud A. El-Badawi, Shinichi Itsuno
Summary: Repetitive Mizoroki-Heck (MH) coupling polymerization was employed to synthesize novel chiral polyureas containing cinchona alkaloids in the main chain. Some chiral polyureas were successfully polymerized through self polycondensation to serve as catalysts for the asymmetric Michael addition reaction. Phenolic-based chiral polymers demonstrated high catalytic activity and excellent enantioselectivities as heterogeneous catalysts for the enantioselective Michael reaction, with the ability to be recycled and reused.
Article
Chemistry, Organic
Deniz Tozendemir, Cihangir Tanyeli
Summary: Cinchona alkaloid-derived organocatalysts have been widely utilized in asymmetric transformations, resulting in products with high enantiopurity. A bifunctional quinine-derived sulfonamide organocatalyst was developed for catalyzing the asymmetric sulfa-Michael reaction, achieving high enantioselectivity with low catalyst loading. The enriched sulfa-Michael addition products were successfully oxidized to obtain the corresponding sulfones.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Kuiliang Li, Xiang Sun, Linge Li, Zhenggen Zha, Feng-Lian Zhang, Zhiyong Wang
Summary: An efficient direct aldol reaction using a chiral copper complex was developed for the synthesis of chiral tertiary alcohol-containing coumaran-3-one derivatives with excellent yields and stereoselectivities.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Applied
Yujiro Hayashi, Masashi Tomikawa, Naoki Mori
Summary: The asymmetric cross-aldol reaction is a synthetically relevant reaction. The reactivity and stereoselectivity of different catalysts were compared for the reaction, and it was found that the proper selection of catalysts can lead to the synthesis of chiral building blocks with high diastereoselectivities and enantioselectivities.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Jihoon Jang, Dae Young Kim
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Multidisciplinary
Yubin Kim, Dae Young Kim
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Multidisciplinary
Jin Wha Park, Subin Jang, Mi Hyeon Choo, Dae Young Kim
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Organic
Jihoon Jang, Rabin Kim, Dae Young Kim
Summary: A photcatalyst-free photoredox synthesis of diaryl selenides has been developed by coupling reaction of diselenides with aryldiazo sulfones. The reaction was accelerated under visible light irradiation without using a photocatalyst or photosensitizer. This approach facilitates the synthesis of diaryl selendes with a wide range of functional group tolerance.
SYNTHETIC COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Yebin Kim, Dae Young Kim
Summary: A novel process for the synthesis of beta-sulfonated cyclopentanones via electrochemical oxidative radical arylsulfonylation and 1,2-alkyl shift sequences of vinyl cyclobutanols has been successfully developed as a practical method under environmentally benign reaction conditions.
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Jihoon Jang, Dae Young Kim
Summary: A new visible light-mediated photocatalytic approach has been developed for the multicomponent synthesis of trifluoromethylated 4H-chromenes from 2-vinyl phenols via trifluoromethylation, oxidation, and cycloaddition reactions, involving the in situ generation of o-quinone methides followed by sequential cyclization.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Kyeong Seop Kim, Dae Young Kim
Summary: This study presents the development of an electrochemical method for bromination and cyclization reactions, which offers an environmentally friendly approach and enables efficient synthesis of bromomethylated gamma-lactone derivatives.
SYNTHETIC COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Kyeong Seop Kim, Dae Young Kim
Summary: In this study, chiral 2-amino-4H-chromene derivatives were synthesized from 2-alkyl-substituted phenol derivatives via a one-pot cascade reaction using a binaphthyl-modified organocatalyst with low catalyst loading (1.25 mol%). The reaction showed moderate to high yields and excellent enantioselectivities.
SYNTHETIC COMMUNICATIONS
(2022)
Article
Chemistry, Organic
Rabin Kim, Jeauk Ha, Jiwon Woo, Dae Young Kim
Summary: An electrochemical oxidative bromination and cyclization sequence was developed for unsaturated carboxylic acids, using bromide anion as bromine radical precursor without external oxidizing reagents. This environmentally-friendly approach offers a facile way to prepare bromomethylated γ-lactones derivatives in moderate to high yields.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Organic
Yebin Kim, Jihoon Jang, Dae Young Kim
Summary: The study introduces a novel approach for synthesizing selenated gamma-lactone derivatives through electrochemical oxidative radical selenylation and cyclization, using stable diselenides as selenium radical precursors. This environmentally friendly method achieves moderate to high yields without the need for external oxidizing reagents.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Jihoon Jang, Dae Young Kim
Summary: This study describes a cyclization reaction utilizing photoredox generated ortho-quinone methides for the synthesis of trifluoromethylated 4H-1-benzopyrans using 1,3-diketones. The process involves the in situ formation of trifluoromethylated ortho-quinone methides from 2-vinyl phenols with Umemoto's reagent, followed by conjugate addition and cyclization reaction with 1,3-diketones.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Jiwoo Park, Dae Young Kim
Summary: A photoredox-catalyzed selenylation and ring closure reaction of alkenoic acid derivatives has been achieved using Rhodamine 6G as an organophotocatalyst under visible light irradiation. The method provides efficient and practical access to structurally diverse selenated gamma-lactones in moderate to high yields.
BULLETIN OF THE KOREAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Organic
Kyeong Seop Kim, Dae Young Kim
Summary: This study describes an electrochemical C-H oxidation/conjugate addition/cyclization reaction that enables the reaction between 2-alkyl phenols and malononitrile under mild reaction conditions, resulting in the synthesis of various 2-amino-4H-chromene derivatives in high yields. This method offers an environmentally friendly approach by eliminating the use of stoichiometric amounts of external redox reagents.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Dae Young Kim
Summary: A one-pot strategy has been developed for the synthesis of multisubstituted 3,4-dihydrocoumarins with high yields and excellent diastereoselectivity. This approach involves C-H oxidation and cyclization cascade reactions of 2-alkyl phenols and oxazolones in the presence of silver oxide and p-toluenesulfonic acid as catalysts.
Article
Chemistry, Organic
Kyeong Seop Kim, Dae Young Kim
Summary: Chiral 3,4-dihydrocoumarin derivatives were synthesized in moderate to high yields with excellent enantioselectivity (up to 96% ee) via a one-pot cascade reaction using a binaphthyl-modified squaramide bifunctional organocatalyst. The reaction involved C-H oxidation and cyclization of 2-benzyl phenols and oxazolones under mild conditions.
ASIAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
